Preparation of Gelatin from Broiler Chicken Stomach Collagen

Abstract

With the increasing consumption of poultry meat around the world, the use of chicken stomachs as a source of collagen is being offered. The objective of this study was to extract gelatin from the stomachs of broiler chickens and to estimate their gel strength, ash content, viscosity, gelling point, melting point, clarity and digestibility. An innovative biotechnological method based on the conditioning of collagen with a microbial endoproteinase (Protamex®) and hot-water extraction was used to control the chemical and thermal denaturation process of collagen to prepare gelatin. The experiments were planned using a Taguchi design, 2 factors at 3 levels; factor A for the amount of proteolytic enzyme (0.10, 0.15 and 0.20%) and factor B for the extraction temperature (55.0, 62.5 and 70.0 °C). Data were statistically processed and analyzed at a significance level of 95%. The gelatin yield averaged 65 ± 8%; the gel strength ranged from 25 ± 1 to 439 ± 6 Bloom, the viscosity from 1.0 ± 0.4 to 3.40 ± 0.03 mPa·s, gelling point from 14.0 ± 2.0 to 22.0 ± 2.0 °C, melting point from 28.0 ± 1.0 to 37.0 ± 1.0 °C. The digestibility of gelatin was 100.0% in all samples; the ash content was very low (0.44 ± 0.02–0.81 ± 0.02%). The optimal conditions for the enzymatic treatment of collagen from chicken stomachs were achieved at a higher temperature (70.0 °C) and a lower amount of enzyme (0.10–0.15%). Conditioning chicken collagen with a microbial endoproteinase is an economically and environmentally friendly processing method, an alternative to the usual acid- or alkaline-based treatment that is used industrially. The extracted products can be used for food and pharmaceutical applications.

Characterization of Poultry Gelatins Prepared by a Biotechnological Method for Targeted Changes at the Molecular Level

“…The properties of the nine gelatins, prepared biotechnologically from chicken stomachs, are included in the study by Prokopová et al [34].…”

“…Poultry stomachs are an unused by-product in some countries, contributing to environmental pollution. However, this tissue contains collagen, which has high added value for the extraction of gelatins and hydrolysates [33,34]. The literature does not currently report the processing poultry stomachs into gelatins using proteolytic enzymes.…”

“…This study builds on previously published articles by the authors [33,34,[39][40][41]. The study aims to determine the antioxidant activity, molecular weight, functional groups, and microbiological population of gelatins prepared from poultry stomachs using an enzymatic method.…”

“…According to the study of Prokopova et al [34], gelatins were prepared from chicken stomachs; each experiment was repeated three times. The extraction of the gelatins occurred according to the Taguchi design, a method of multifactorial experiments that allows for a statistical evaluation and exploration of the influence of independent variables (processing factors) on dependent variables, making the process less variable [71].…”

Sorption Isotherms and Thermodynamic Characteristics of Gelatin Powder Extracted from Whitefish Skin: Mathematical Modeling Approach

“…Gelatin is thermally denatured collagen from bones, hides, organs, and skins from animals like pigs, fish, cows, chickens, and others [ 1 ]. The global demand for gelatin has been steadily increasing, reaching an annual production output of 677,200 tons in 2021 [ 2 ]. The predominant sources of gelatin are pork and beef skin or bones.…”